Tire mounting machine

Abstract

A tire holding device of a tire mounting machine grasps the bead section of a green tire by chucking paddles and places the green tire around an upright cylindrical vulcanization bladder. A bladder device of the tire mounting machine expands the vulcanization bladder to press same against the inner surface of the green tire, and sets the green tire in a vulcanization-mold. On a lower portion of each chucking paddle, guide extensions are formed to extend in the two circumferential directions. Between adjacent chucking paddles, the guide extensions extend toward each other and constantly overlap each other to prevent the expanding vulcanization bladder from contacting the radially inner surface of the bead section and from stripping the non-vulcanized rubber of the green tire.

The invention claimed is: 
     
       1. A tire mounting machine comprising:
 a tire holding device including vertically oriented card-shaped chucking paddles arranged in side-by-side disposition to be included in an imaginary circular cylinder with a circumferential spacing between adjoining chucking paddles, in such a manner that the card-shaped chucking paddles are concurrently movable radially outward and inward to increase and decrease a diameter of the imaginary circular cylinder, the tire holding device being adapted to hold a green tire from inside the tire positioned around the tire holding device, when the diameter thereof is increased; and 
 a bladder device provided with a tubular upright vulcanization bladder to be positioned in a center of a vulcanization-mold and adapted to be inflated by supply of a shaping gas thereinto, the tubular vulcanization bladder having a lower opening held and closed by a lower clamp ring and an upper opening held and closed by an upper clamp ring, the upper opening of the vulcanization bladder being movable vertically in a region above the lower clamp ring; 
 wherein the tire holding device is operable to hold a bead section of the green tire by means of the chucking paddles and to carry the thus held green tire around the upright vulcanization bladder, while the bladder device is operable to inflate the vulcanization bladder by supplying the shaping gas into the vulcanization bladder concurrently with lowering of the upper clamp ring, thereby to cause the vulcanization bladder to be pressed against an internal surface of the green tire for setting the green tire in the vulcanization-mold: wherein: 
 each of the chucking paddles has, on a lower portion thereof, guide extensions on two lateral sides thereof extending in circumferential directions; and 
 the chucking paddles have their guide extensions protruding to reach the guide extensions of circumferentially adjoining chucking paddles in mutually and constantly overlapping disposition. 
 
     
     
       2. The tire mounting machine as defined in  claim 1 , wherein:
 the guide extensions protruding in the circumferential directions from the lateral sides of the chucking paddles have an arcuate shape of a same predetermined radius of curvature; and 
 the tire holding device has a maximum diameter of the green tire that can be held thereby, the maximum diameter being a diameter of an imaginary circular cylinder defined by the guide extensions of the chucking paddles by which the green tire is held. 
 
     
     
       3. The tire mounting machine as defined in  claim 2 , wherein the guide extensions on one lateral sides of the chucking paddles overlap the guide extensions on the other lateral sides of the chucking paddles, on radially inner sides of the guide extensions on the other lateral sides with respect to the imaginary cylinder. 
     
     
       4. The tire mounting machine as defined in  claim 2 , wherein the chucking paddles are arranged such that radial movement of the chucking paddles in radial directions of the imaginary cylinder changes an outer diameter of the imaginary cylinder, and that the radial movement of the chucking paddles causes resilient deformation of the guide extensions. 
     
     
       5. The tire mounting machine as defined in  claim 3 , wherein:
 an urging element is provided to urge the chucking paddles into a basic attitude in which all the radially inner surfaces of the chucking paddles face a center axis of the imaginary cylinder to be constituted by the chucking paddles; and 
 the urging element is operative to urge the chucking paddles in such mutual disposition that tip ends of the guide extensions on the one lateral sides of the chucking paddles are kept in constant sliding contact with radially inner surfaces of the guide extensions on the other lateral sides of the chucking paddles. 
 
     
     
       6. The tire mounting machine as defined in  claim 5 , wherein:
 the urging element is an annular spring member for urging the chucking paddles radially inward from radially outer side thereof; and 
 the annular spring member is changeable in diameter in conformity with radial movement of the chucking paddles, so as to constantly exert a force urging the chucking paddles into the basic attitude. 
 
     
     
       7. The tire mounting machine as defined in  claim 3 , wherein the chucking paddles are arranged such that radial movement of the chucking paddles in radial directions of the imaginary cylinder changes an outer diameter of the imaginary cylinder, and that the radial movement of the chucking paddles causes resilient deformation of the guide extensions.